The formulation of a hypothesis for any pair of nonempty finite languages is considered. The hypothesis consists in the formulation of the necessary conditions for the equality of infinite iterations of these languages, ...

The geometric-arithmetic index is a topological index was defined as $GA(G)=\sum{uv\in E(G)}\frac{2\sqrt{d_ud_v}}{d_u+d_v}}$, where du denotes the degree of vertex u in G. By replacing instead $\delta_u=\sum_{v\cong u} ...

The energy, E(G), of a simple graph G is defined to be the sum of the absolute values of the eigen values of G. In this paper, we introduce some in-equalities of energy of graphs.

The field of mathematical chemistry started with the pure and memorable activities of Alireza Ashrafi in Iran. One of the most important factors in the rapid expansion of this branchof science in Iran, which intensified ...

The symmetric division deg index (or simply SDD) was proposed by Vukicevic et al.as a remarkable predictor of total surface area of polychlorobiphenyls. We are interested in how the SDD of a graph changes when edges are ...

A power graph is defined a graph that it's vertices are the elements of group and two vertices are adjacent if and only if one of them is a power of the other. Suppose $A(X)$ is the adjacency matrix of graph $X$. Then the ...